The effect of low voltage and low concentration contrast agent on image quality of coronary CT angiography,radiation dose and iodine intake was evaluated.A total of 121 patients with body mass index(BMI)<26 kg/m2 a...The effect of low voltage and low concentration contrast agent on image quality of coronary CT angiography,radiation dose and iodine intake was evaluated.A total of 121 patients with body mass index(BMI)<26 kg/m2 and heart rate(HR)<70 beats/min were randomly divided into four groups:group A(n=31,80 kVp,270 mgl/mL);group B(n=33,100 kVp,270 mgl/mL);group C(h=30,100 kVp,320 mgl/mL);group D(w=27,100 kVp,400 mgl/mL).The automatic current modulation system and the iterative algorithm for reconstruction were adopted in each group.The CT values and SD values of the aortic root(AR),subcutaneous fat,left coronary artery opening(LCA),and right coronary artery opening(RCA)were measured in all groups,the signalto-noise ratio(SNR)and contrast noise ratio(CNR)were calculated,and effective radiation dose and iodine intake were recorded.The subjective assessment for image quality was performed by two physicians using a 4-point scale.The results were compared using the one-way ANOVA and rank sum tests.The image quality of the four groups met the clinical diagnostic requirements.The CT values of AR in groups A,B,C,and D were 537.6±71.4,447.2±81.9,445.2±64.9 and 518.5±94.9 Hu,respectively,with no significant difference between group A and group D,or between group B and group C,while CT values in groups B and C were significantly lower than those in groups A and D(P<0.05).In groups A,B,C,and D,the LCA SNR values were 22.7±9.1,23.3±9.1,23.3±7.7 and 26.6±8.9,and the RCA CNR values were 26.9±9.&28.5±11.4,27.7土&8 and 32」±10.6,respectively.The AR visual scores in groups A,B,C and D were 3.8±0.2,3.9±0.3,3.9±0.3 and 4.0±0.3,respectively.There were no significant differences in SNR,CNR and visual score among the four groups(P>0.05).The radiation doses in groups A,B,C and D were 2.6±1.4,3.6±1.&4.9±3.5 and 4.9±2.8 mSv,respectively.The radiation dose in group A was significantly less than that in the rest three groups(P<0.05).The iodine intakes in groups A,B,C and D were 14.9±1.5,15.0±1.5,17.7±2.0 and 18.1±2.5 g,respectively.There was no significant difference in the intake of iodine between groups C and D,or between groups A and B,while iodine intake in groups A and B were significantly reduced as compared with that in groups C and D(P<0.05).It was concluded that for patients with low BMI and controlled HR,compared to 100 kVp tube voltage combined with multiple concentration contrast agents,80 kVp combined with 270 mgl/mL contrast agent is enough to ensure the quality of the images,and can reduce the radiation dose significantly,while reducing the amount of iodine intake notably,thus reducing the incidence of adverse reaction.展开更多
Background: Chronic kidney disease patients are at a greater risk for nephropathy requiring dialysis after percutaneous coronary intervention. Such patients are usually deferred due to fear of “Renalism”.?Objectives...Background: Chronic kidney disease patients are at a greater risk for nephropathy requiring dialysis after percutaneous coronary intervention. Such patients are usually deferred due to fear of “Renalism”.?Objectives This study assesses the outcome of Low dose contrast protocol during PCI in CKD patients whose e-GFR 60 ml/min/1.72 m and investigates a safety margin for contrast use in these high-risk categories.?Methods: Patients were into three groups according to CV/e-GFR ratio: Group (A) low-dose: CV/e-GFR ratio 2.0 Group (B) medium-dose: CV/e-GFR ratio > 2.0 and × bodyweight\s.creatinine). Group (C) high-dose: CV/e-GFR ratio > MACD. Results: A total of 73 patients were enrolled. Average age was 54 ± 8 years,81.4% were male and 18.6% were females and 52% were diabetic. Mean baseline e-GFR was 40 ± 8.0 ml/min/1.73m2. Contrast Volume used in group A was (58.26 ± 15.05) (n = 24), in group B (109.42 ± 17.11) (n = 26) and in group C (304.5 ± 60.30) (n = 23), respectively. The incidences of CI-AKI in the 3 groups were 0%, 11.5% and 35%, respectively (p = 0.02). All-cause death 0%, 17% and introduction of maintenance hemo dialysis was 0%, 11.5% and 26%, respectively (p Conclusion: Low dose contrast protocol is safe, effective and easily applicable technique without CI-AKI or death.展开更多
Objective To evaluate the clinical value of myocardial perfusion imaging with dual-source dual-energy CT and a contrast agent at a low concentration in the diagnosis of myocardial infarction in the elderly.Methods One...Objective To evaluate the clinical value of myocardial perfusion imaging with dual-source dual-energy CT and a contrast agent at a low concentration in the diagnosis of myocardial infarction in the elderly.Methods Onestop cardiac imaging with dual-source CT was conducted in 138 elderly patients diagnosed with myocardial infarction between October 2015 and May 2016.The展开更多
AIM:To evaluate the feasibility of low contrast medium and radiation dose for hepatic computed tomography(CT) perfusion of rabbit VX2 tumor.METHODS:Eleven rabbits with hepatic VX2 tumor underwent perfusion CT scanning...AIM:To evaluate the feasibility of low contrast medium and radiation dose for hepatic computed tomography(CT) perfusion of rabbit VX2 tumor.METHODS:Eleven rabbits with hepatic VX2 tumor underwent perfusion CT scanning with a 24-h interval between a conventional tube potential(120 k Vp) protocol with 350 mg I/m L contrast medium and filtered back projection,and a low tube potential(80 k Vp) protocol with 270 mg I/m L contrast medium with iterative reconstruction.Correlation and agreement among perfusion parameters acquired by the conventional and low dose protocols were assessed for the viable tumor component as well as whole tumor.Image noise and tumor-to-liver contrast to noise ratio during arterial and portal venous phases were evaluated.RESULTS:A 38% reduction in contrast medium dose(360.1 ± 13.3 mg I/kg vs 583.5 ± 21.5 mg I/kg,P < 0.001) and a 73% decrease in radiation dose(1898.5 m Gy·cm vs 6951.8 m Gy·cm) were observed.Interestingly,there was a strong positive correlation in hepatic arterial perfusion(r = 0.907,P < 0.001;r = 0.879,P < 0.001),hepatic portal perfusion(r = 0.819,P = 0.002;r = 0.831,P = 0.002),and hepatic blood flow(r = 0.945,P < 0.001;r = 0.930,P < 0.001) as well as a moderate correlation in hepatic perfusion index(r = 0.736,P = 0.01;r = 0.636,P = 0.035) between the low dose protocol with iterative reconstruction and the conventional protocol for the viable tumor component and the whole tumor.These two imaging protocols provided a moderate but acceptable agreement for perfusion parameters and similar tumorto-liver CNR during arterial and portal venous phases(5.63 ± 2.38 vs 6.16 ± 2.60,P = 0.814;4.60 ± 1.27 vs 5.11 ± 1.74,P = 0.587).CONCLUSION:Compared with the conventional protocol,low contrast medium and radiation dose with iterative reconstruction has no significant influence on hepatic perfusion parameters for rabbits VX2 tumor.展开更多
AIM To assess the effect of neutral(NC) and positive(PC) oral contrast use on patient dose in low-dose abdominal computed tomography(CT).METHODS Low-dose clinically indicated CTs were performed on 79 Crohn's patie...AIM To assess the effect of neutral(NC) and positive(PC) oral contrast use on patient dose in low-dose abdominal computed tomography(CT).METHODS Low-dose clinically indicated CTs were performed on 79 Crohn's patients(35 = PC, 1 L 2% gastrografin; 44 = NC, 1.5 L polyethylene glycol). Scanner settings for both acquisitions were identical apart from 25 s difference in intravenous contrast timing. Body mass index(BMI), scan-ranges, dose-length product and size-specific dose estimated were recorded. Data was reconstructed with pure model-based iterative reconstruction. Image quality was objectively and subjectively analysed. Data analysis was performed with Statistical Package for Social Scientists.RESULTS Higher doses were seen in neutral contrast CTs(107.60 ± 78.7 m Gy.cm, 2.47 ± 1.21 m Gy vs 85.65 ± 58.2 m Gy.cm, 2.18 ± 0.96 m Gy). The differencehad both NC and PC investigations. Image-quality assessment yielded 6952 datapoints. NC image quality was significantly superior(P < 0.001)(objective noise, objective signal to noise ratio, subjective spatial resolution, subjective contrast resolution, diagnostic acceptability) at all levels. NC bowel distension was significantly(P < 0.001) superior.CONCLUSION The use of polyethylene glycol as a neutral OC agent leads to higher radiation doses than standard positive contrast studies, in low dose abdominal CT imaging. This is possibly related to the osmotic effect of the agent resulting in larger intraluminal fluid volumes and resultant increased overall beam attenuation.展开更多
目的探讨高频超声造影(CEUS)在浅表肝脏局灶性病变(FLLs)检出及诊断中的临床价值。方法选取我院浅表FLLs患者38例,共63个病变,分别使用低频凸阵探头和高频线阵探头对患者进行CEUS检查,比较低频CEUS与高频CEUS在病变可见度评分、检出率...目的探讨高频超声造影(CEUS)在浅表肝脏局灶性病变(FLLs)检出及诊断中的临床价值。方法选取我院浅表FLLs患者38例,共63个病变,分别使用低频凸阵探头和高频线阵探头对患者进行CEUS检查,比较低频CEUS与高频CEUS在病变可见度评分、检出率和良恶性鉴别诊断中的差异。结果浅表FLLs在高频CEUS下平均可见度评分和检出率分别为(3.62±0.79)分、93.7%(59/63),均显著高于低频CEUS[(2.44±1.04)分、57.1%(36/63)],差异均有统计学意义(均P<0.05)。高频CEUS对最大径≤1 cm FLLs、最大径1~2 cm FLLs和肝转移瘤的检出率均显著高于低频CEUS[96.7%(29/30)vs.46.7%(14/30)、92.6%(25/27)vs.66.7%(18/27)、100%(26/26)vs.57.7%(15/26)],差异均有统计学意义(均P<0.001)。高频CEUS鉴别诊断浅表FLLs良恶性的灵敏度、准确率分别为92.9%、91.7%,均高于低频CEUS(78.6%、77.8%),差异均有统计学意义(均P<0.05)。结论高频CEUS在提高浅表FLLs的检出率和定性诊断方面均有明显优势,具有重要的临床价值。展开更多
文摘The effect of low voltage and low concentration contrast agent on image quality of coronary CT angiography,radiation dose and iodine intake was evaluated.A total of 121 patients with body mass index(BMI)<26 kg/m2 and heart rate(HR)<70 beats/min were randomly divided into four groups:group A(n=31,80 kVp,270 mgl/mL);group B(n=33,100 kVp,270 mgl/mL);group C(h=30,100 kVp,320 mgl/mL);group D(w=27,100 kVp,400 mgl/mL).The automatic current modulation system and the iterative algorithm for reconstruction were adopted in each group.The CT values and SD values of the aortic root(AR),subcutaneous fat,left coronary artery opening(LCA),and right coronary artery opening(RCA)were measured in all groups,the signalto-noise ratio(SNR)and contrast noise ratio(CNR)were calculated,and effective radiation dose and iodine intake were recorded.The subjective assessment for image quality was performed by two physicians using a 4-point scale.The results were compared using the one-way ANOVA and rank sum tests.The image quality of the four groups met the clinical diagnostic requirements.The CT values of AR in groups A,B,C,and D were 537.6±71.4,447.2±81.9,445.2±64.9 and 518.5±94.9 Hu,respectively,with no significant difference between group A and group D,or between group B and group C,while CT values in groups B and C were significantly lower than those in groups A and D(P<0.05).In groups A,B,C,and D,the LCA SNR values were 22.7±9.1,23.3±9.1,23.3±7.7 and 26.6±8.9,and the RCA CNR values were 26.9±9.&28.5±11.4,27.7土&8 and 32」±10.6,respectively.The AR visual scores in groups A,B,C and D were 3.8±0.2,3.9±0.3,3.9±0.3 and 4.0±0.3,respectively.There were no significant differences in SNR,CNR and visual score among the four groups(P>0.05).The radiation doses in groups A,B,C and D were 2.6±1.4,3.6±1.&4.9±3.5 and 4.9±2.8 mSv,respectively.The radiation dose in group A was significantly less than that in the rest three groups(P<0.05).The iodine intakes in groups A,B,C and D were 14.9±1.5,15.0±1.5,17.7±2.0 and 18.1±2.5 g,respectively.There was no significant difference in the intake of iodine between groups C and D,or between groups A and B,while iodine intake in groups A and B were significantly reduced as compared with that in groups C and D(P<0.05).It was concluded that for patients with low BMI and controlled HR,compared to 100 kVp tube voltage combined with multiple concentration contrast agents,80 kVp combined with 270 mgl/mL contrast agent is enough to ensure the quality of the images,and can reduce the radiation dose significantly,while reducing the amount of iodine intake notably,thus reducing the incidence of adverse reaction.
文摘Background: Chronic kidney disease patients are at a greater risk for nephropathy requiring dialysis after percutaneous coronary intervention. Such patients are usually deferred due to fear of “Renalism”.?Objectives This study assesses the outcome of Low dose contrast protocol during PCI in CKD patients whose e-GFR 60 ml/min/1.72 m and investigates a safety margin for contrast use in these high-risk categories.?Methods: Patients were into three groups according to CV/e-GFR ratio: Group (A) low-dose: CV/e-GFR ratio 2.0 Group (B) medium-dose: CV/e-GFR ratio > 2.0 and × bodyweight\s.creatinine). Group (C) high-dose: CV/e-GFR ratio > MACD. Results: A total of 73 patients were enrolled. Average age was 54 ± 8 years,81.4% were male and 18.6% were females and 52% were diabetic. Mean baseline e-GFR was 40 ± 8.0 ml/min/1.73m2. Contrast Volume used in group A was (58.26 ± 15.05) (n = 24), in group B (109.42 ± 17.11) (n = 26) and in group C (304.5 ± 60.30) (n = 23), respectively. The incidences of CI-AKI in the 3 groups were 0%, 11.5% and 35%, respectively (p = 0.02). All-cause death 0%, 17% and introduction of maintenance hemo dialysis was 0%, 11.5% and 26%, respectively (p Conclusion: Low dose contrast protocol is safe, effective and easily applicable technique without CI-AKI or death.
文摘Objective To evaluate the clinical value of myocardial perfusion imaging with dual-source dual-energy CT and a contrast agent at a low concentration in the diagnosis of myocardial infarction in the elderly.Methods Onestop cardiac imaging with dual-source CT was conducted in 138 elderly patients diagnosed with myocardial infarction between October 2015 and May 2016.The
基金National Natural Science Foundation of China,No.NSFC 81171389Key Program of Basic Research from Shanghai Municipal Science and Technology Commission,No.12JC1406500the Program of Shanghai Municipal Health Outstanding Discipline Leader,No.XBR 2013110
文摘AIM:To evaluate the feasibility of low contrast medium and radiation dose for hepatic computed tomography(CT) perfusion of rabbit VX2 tumor.METHODS:Eleven rabbits with hepatic VX2 tumor underwent perfusion CT scanning with a 24-h interval between a conventional tube potential(120 k Vp) protocol with 350 mg I/m L contrast medium and filtered back projection,and a low tube potential(80 k Vp) protocol with 270 mg I/m L contrast medium with iterative reconstruction.Correlation and agreement among perfusion parameters acquired by the conventional and low dose protocols were assessed for the viable tumor component as well as whole tumor.Image noise and tumor-to-liver contrast to noise ratio during arterial and portal venous phases were evaluated.RESULTS:A 38% reduction in contrast medium dose(360.1 ± 13.3 mg I/kg vs 583.5 ± 21.5 mg I/kg,P < 0.001) and a 73% decrease in radiation dose(1898.5 m Gy·cm vs 6951.8 m Gy·cm) were observed.Interestingly,there was a strong positive correlation in hepatic arterial perfusion(r = 0.907,P < 0.001;r = 0.879,P < 0.001),hepatic portal perfusion(r = 0.819,P = 0.002;r = 0.831,P = 0.002),and hepatic blood flow(r = 0.945,P < 0.001;r = 0.930,P < 0.001) as well as a moderate correlation in hepatic perfusion index(r = 0.736,P = 0.01;r = 0.636,P = 0.035) between the low dose protocol with iterative reconstruction and the conventional protocol for the viable tumor component and the whole tumor.These two imaging protocols provided a moderate but acceptable agreement for perfusion parameters and similar tumorto-liver CNR during arterial and portal venous phases(5.63 ± 2.38 vs 6.16 ± 2.60,P = 0.814;4.60 ± 1.27 vs 5.11 ± 1.74,P = 0.587).CONCLUSION:Compared with the conventional protocol,low contrast medium and radiation dose with iterative reconstruction has no significant influence on hepatic perfusion parameters for rabbits VX2 tumor.
文摘AIM To assess the effect of neutral(NC) and positive(PC) oral contrast use on patient dose in low-dose abdominal computed tomography(CT).METHODS Low-dose clinically indicated CTs were performed on 79 Crohn's patients(35 = PC, 1 L 2% gastrografin; 44 = NC, 1.5 L polyethylene glycol). Scanner settings for both acquisitions were identical apart from 25 s difference in intravenous contrast timing. Body mass index(BMI), scan-ranges, dose-length product and size-specific dose estimated were recorded. Data was reconstructed with pure model-based iterative reconstruction. Image quality was objectively and subjectively analysed. Data analysis was performed with Statistical Package for Social Scientists.RESULTS Higher doses were seen in neutral contrast CTs(107.60 ± 78.7 m Gy.cm, 2.47 ± 1.21 m Gy vs 85.65 ± 58.2 m Gy.cm, 2.18 ± 0.96 m Gy). The differencehad both NC and PC investigations. Image-quality assessment yielded 6952 datapoints. NC image quality was significantly superior(P < 0.001)(objective noise, objective signal to noise ratio, subjective spatial resolution, subjective contrast resolution, diagnostic acceptability) at all levels. NC bowel distension was significantly(P < 0.001) superior.CONCLUSION The use of polyethylene glycol as a neutral OC agent leads to higher radiation doses than standard positive contrast studies, in low dose abdominal CT imaging. This is possibly related to the osmotic effect of the agent resulting in larger intraluminal fluid volumes and resultant increased overall beam attenuation.
文摘目的探讨高频超声造影(CEUS)在浅表肝脏局灶性病变(FLLs)检出及诊断中的临床价值。方法选取我院浅表FLLs患者38例,共63个病变,分别使用低频凸阵探头和高频线阵探头对患者进行CEUS检查,比较低频CEUS与高频CEUS在病变可见度评分、检出率和良恶性鉴别诊断中的差异。结果浅表FLLs在高频CEUS下平均可见度评分和检出率分别为(3.62±0.79)分、93.7%(59/63),均显著高于低频CEUS[(2.44±1.04)分、57.1%(36/63)],差异均有统计学意义(均P<0.05)。高频CEUS对最大径≤1 cm FLLs、最大径1~2 cm FLLs和肝转移瘤的检出率均显著高于低频CEUS[96.7%(29/30)vs.46.7%(14/30)、92.6%(25/27)vs.66.7%(18/27)、100%(26/26)vs.57.7%(15/26)],差异均有统计学意义(均P<0.001)。高频CEUS鉴别诊断浅表FLLs良恶性的灵敏度、准确率分别为92.9%、91.7%,均高于低频CEUS(78.6%、77.8%),差异均有统计学意义(均P<0.05)。结论高频CEUS在提高浅表FLLs的检出率和定性诊断方面均有明显优势,具有重要的临床价值。
